Inside filter for aquariums

Abstract

A bottom aquarium filter for an aquarium tank including a substantially cylindrical container having an inwardly directed concave forward wall. A grill wall removably coupled onto the concave forward wall and defining therewith an inlet chamber. A removable L-shaped insert member includes a substantially circular perforated platform wall and an upstanding convex partition wall. The platform wall spacedly sits on the bottom of the container and defines with the container a filtration chamber above the platform and a clear water chamber beneath the platform. The partition wall mates in opposition against a rear peripheral section of the circular wall of the container and defines therewith an air lift chamber. A removable cover mounts onto the container and includes a mouth aligned with the air lift chamber. The cover serves to retain all of the members in unitary assembly. An air tube fits into a spout projecting from the rear peripheral wall and extends into the air lift chamber terminating in an air diffuser which sits in a depressed compartment beneath the base wall of the container. The air tube can serve as a handle for lifting the filter assembly. The assembly can be easily separated for cleaning without the difficulty in reaching any portion of pre-formed compartments.

I claim: 
     
       1. An aquarium filter for an aquarium tank, said filter comprising in combination: a container having a forward wall, a grill member coupled in opposition to said forward wall to define therewith an inlet chamber for receiving contaminated water from the aquarium, a removable insert member having a perforated platform wall and an upstanding partition wall, said platform wall spacedly sitting onto the bottom of said container and defining with said container a filter chamber above said platform wall and a clear water chamber beneath said platform wall, said partition wall mating in opposition to a rear peripheral wall of said container and defining therewith an air lift chamber, and a removable cover member for mounting onto said container and including a mouth aligned with said air lift chamber, whereby contaminated water from said inlet chamber can flow over said forward wall and into said filter chamber where said contaminated water is substantially decontaminated before passing through said perforated platform to said clear water chamber for egress through said air lift chamber and out of said mouth back into the aquarium, and further comprising a depression formed into the bottom of the container within said clear water chamber, and a protruding instep portion at the junction between said platform wall and said partition wall for mating with said depression to define a receiving chamber for receiving an air diffuser, whereby at least a portion of the air diffuser is positioned below said platform wall to effectively extend the depth of the air lift chamber below the air water chamber, placing the air diffuser out of the air lift chamber so as not to block the air lift chamber and directing the air into the space under said instep to provide greater clean water flow into the air lift chamber.   
     
     
       2. An aquarium filter as in claim 1, wherein the forward portion of said air diffuser receiving chamber comprises means to direct air flow from the air diffuser to said air lift chamber. 
     
     
       3. An aquarium filter as in claim 1, and comprising a pedestal depending from said container, an integral hollow neck portion interconnecting said container with said pedestal, said hollow neck portion being in flow communication with said air lift chamber to effectively increase the depth of said air lift chamber below the clear water chamber, and wherein said depression is formed into said neck portion. 
     
     
       4. An aquarium filter as in claim 3, wherein said container, said neck portion and said pedestal are integral and form unitary structure, and said air diffuser extends into said neck portion.